(1 of )Liliana Contreras-Salgado sits with her daughters Gloria, 2, left, and Fatima, 6, in front of where their home used to be before it was destroyed by fire in Santa Rosa, on Monday, October 9, 2017. (BETH SCHLANKER/ The Press Democrat)

(2 of )Chris Cortese looks to salvage something from his parents home after it was destroyed by fire in Santa Rosa, on Monday, October 9, 2017. (BETH SCHLANKER/ The Press Democrat)

(3 of )The northeast entrance of the Luther Burbank Center for the Arts after the Tubbs Fire burned through north Santa Rosa, California on Monday, October 9, 2017. (Alvin Jornada / The Press Democrat)

(5 of )Wine Country wildfires: A string of blazes broke across Napa County late Sunday and early and Monday. Fueled by heavy winds, they grew rapidly, destroying homes and forcing evacuation across the region. (Updated Monday night October 9, 2017)

(6 of )Liliana Contreras-Salgado sits with her daughters Gloria, 2, left, and Fatima, 6, in front of where their home used to be before it was destroyed by fire in Santa Rosa, on Monday, October 9, 2017. (BETH SCHLANKER/ The Press Democrat)

(7 of )San Francisco firefighters works to put out a house fire on Monday, October 9, 2017 in Glen Ellen, California . (BETH SCHLANKER/The Press Democrat)

(8 of )Residents are evacuated from the Sonoma Developmental Center as fire began to burn building on Monday, October 9, 2017 in Glen Ellen, California . (BETH SCHLANKER/The Press Democrat)

(10 of )A home burns in the Fountaingrove area on Monday, October 9, 2017 in Santa Rosa, California . (BETH SCHLANKER/The Press Democrat)

(11 of )Chris Neace puts water on a structure fire in an attempt to keep the fire from spreading to another home in the Fountaingrove area of Santa Rosa on Monday, October 9, 2017. (Christopher Chung/ The Press Democrat)

(12 of )The Wikiup area is engulfed in flames in Santa Rosa early Monday morning, October 9, 2017.
(Christopher Chung/ The Press Democrat)

(13 of )Homes along Paxton Place are reduced to rubble in the Fountaingrove area of Santa Rosa on Monday, October 9, 2017.
(Christopher Chung/ The Press Democrat)

(14 of )Santa Rosa Fire Station 5 in the Fountaingrove area of Santa Rosa is gutted by fire on Monday, October 9, 2017. (Christopher Chung/ The Press Democrat)

(15 of )A Bodega Bay volunteer firefighting crew works on protecting a structure by trying to knock down flames on a neighboring house near Alturia Heights, in Fountaingrove area of Santa Rosa on Monday, October 9, 2017.
(Christopher Chung/ The Press Democrat)

(16 of )Sandy DeGidio becomes emotional after her home was destroyed by fire in Santa Rosa, on Monday, October 9, 2017. (BETH SCHLANKER/ The Press Democrat)

A raging firestorm born in the dark of night by dry, violent winds roared down from the rural hills bordering Napa and Sonoma counties early Monday and cut a devastating swath into Santa Rosa from its eastern outskirts, killing at least seven city residents and destroying more than 1,500 structures.

Tens of thousands of people were forced to flee their homes hours before sunrise, when the ruin wrought by flames in several terrifying hours became apparent over a rural and urban landscape spanning more than 50 square miles. In Sonoma County alone, officials said 100 people were reported missing.

For thousands of firefighters and residents trying to protect homes, the fire driven by gusts up to 68 mph was an amorphous, unstoppable force, rampaging through Mark West Springs, Larkfield and Wikiup, and Fountaingrove, where it claimed hundreds of upscale Santa Rosa houses tucked into forested hillsides.

From there it raced on, scorching landmark businesses and school campuses and threatening two hospitals, where hundreds of patients were evacuated. Throwing sparks ahead of its main front, the fire then jumped Highway 101 into a heavily populated corner of northwest Santa Rosa.

In Coffey Park, the destruction was warlike. Block after block, hundreds of homes burst into flames.

“The volume of structures and neighborhoods that have been completely destroyed is incredible,” said Assistant Santa Rosa Fire Marshal Paul Lowenthal, who lost his own Larkfield home Monday. “There are areas where, as far as the eye can see, is complete devastation with entire neighborhoods burned to the ground.”

By nightfall Monday, the Tubbs fire, which began about 10 p.m. near Calistoga in eastern Napa County, was still uncontrolled on many fronts. Its single-day toll made it the worst natural disaster on record in Sonoma County, and among the most destructive wildfires in California history. Authorities said they expected the death toll to grow, and financial losses from the fire — from homes and luxury hotels, to school campuses and wineries — are likely to mount into the billions of dollars.

The blaze, which burned 27,000 acres by Monday night, was the most catastrophic of more than 14 wildfires across eight counties in Northern California. The heaviest activity centered in Sonoma, Napa, Mendocino and Lake counties, where up to 75,000 acres had burned. A total of 11 people were confirmed dead in the local fires, including two in Mendocino County and an elderly couple in Napa County.

In Sonoma Valley, several fires burned 5,000 acres around Glen Ellen and Kenwood, where homes on both sides of Highway 12 were destroyed.

“It has been a horrific and terrifying night for a great many people,” acting Santa Rosa Police Chief Craig Schwartz said Monday during a news conference. Low humidity and strong, inland winds that developed over the weekend helped fuel the firestorm. Cal Fire and the National Weather Service issued a red flag warning that extended through today, though gusts had largely died down by Monday evening.

By that time, the nightmare that many wildfire experts had long feared in Santa Rosa had played out. It was a haunting sequel to the disastrous Hanly fire of 1964, which originated in the same rugged terrain along the Napa-Sonoma border and ripped through what was then mostly rural land. It was halted before it reached the city’s core.

Flames outpaced overmatched fire crews, burning through wooded, rural estates and onto paved city blocks. Desperate residents asked all day for updates on active fire fronts that seemed to have them surrounded. Fire officials pleaded for reinforcements.

Highway 101 in Santa Rosa was completely shut down in both directions, from Steele Lane to Mark West Springs Road. Thick smoke kept badly needed Cal Fire tankers and helicopters grounded for much of the day. Commercial flights at Charles. M. Schulz-Sonoma County Airport were canceled.

With hours to go before sunrise, the fire had topped a ridge west of Santa Rosa, lighting the hillside with flames before swooping down into town.

Ted Regan, who lives near Calistoga Road, said he saw the glow from the foothills behind his house about 2 a.m.

“It got brighter and brighter and then we saw flames. That’s when we said, ‘It’s time to go,’” Regan said.

Rachel McKenzie, who fled her home south of Hopper Avenue in northwest Santa Rosa with her son, her husband and a crate filled with pet reptiles, described the frenzied evacuation hours later as she awaited news of her home at an emergency evacuation center.

“It was totally chaotic,” McKenzie said. “I saw a fire start in my neighbor’s house, and it was fully engulfed when we drove away.”

Work to evacuate patients from Kaiser Permanente and Sutter Santa Rosa hospitals in north Santa Rosa began in darkness as windblown smoke blanketed the Highway 101 corridor. In the hills, and later in the flatlands, residents were alerted to the fire’s approach by evacuation orders, made by reverse emergency calls and loudspeaker transmissions, and officers knocking on doors.

“These blazes have taken place at an individual’s most vulnerable time, when they are home and in bed,” State Sen. Mike McGuire, D-Healdsburg, said.

By midday, the evacuation orders included Oakmont — the Sonoma Valley retirement community — Windsor’s southern outskirts and the eastern border of Rohnert Park.

By that time, a large Mendocino Avenue mobile home park was left in smoldering ruins. About half of Cardinal Newman High School was destroyed along with landmarks including the Fountaingrove Inn, the Hilton Sonoma Wine Country and the historic Fountaingrove Round Barn. The Luther Burbank Center for the Arts was partially damaged and Paradise Ridge winery suffered extensive damage.

Sonoma County Supervisor Shirlee Zane, who surveyed the damage Monday afternoon from a helicopter described the burned landscape as “a hellish war zone.”

“It looked like somebody bombed these neighborhoods,” she said.

Pacific Gas and Electric Co. reported 50,000 Sonoma County customers were without power Monday. Cellphone coverage was intermittent throughout Monday as flames knocked out communication equipment in the region.

“Due to wildfires, some wireless customers in Sonoma, Napa, Mendocino and Humboldt counties and their surrounding areas may be experiencing issues with their wireless services,” said Leland Kim, media relations director for AT&T. “We are working to restore service as quickly as possible.”

Gov. Jerry Brown declared a state of emergency in Napa, Sonoma, Mendocino and Yuba counties as well as others throughout the state. Sonoma County’s two congressmen, Jared Huffman, D-San Rafael, and Mike Thompson, D-St. Helena, traveled to the area Monday, and Thompson joined Zane in the aerial survey.

He said he already had forwarded photos to the Federal Emergency Man-

agement Agency and the White House.

The cause of the Tubbs fire remains undetermined, though any small spark could have been fanned into a conflagration by the gusts Sunday night, Cal Fire officials said.

It started near Highway 128 and Bennett Lane north of Calistoga and spread southwest into Sonoma County through heavily wooded areas along Mark West Creek and Mark West Springs Road.

Explosions from bursting propane tanks punctuated the night as flames set the sky aglow. Sunup Monday was otherworldly, with a blood-red sun obscured by smoke, ash blanketing the ground and residents rushing to fill up gas tanks and seek emergency shelter.

“It was like an apocalypse,” said Laura Mills, who lives on Wedgewood Way in Fountaingrove, and was forced to evacuate in bumper-to-bumper traffic to the Finley Community Center. “It was very spooky.”

Evacuation centers countywide filled through the day with anxious, exhausted people uncertain of what awaited them at home. Those awakened for hasty departures the previous night included assisted living and senior home residents.

Roads, schools and businesses around the area were closed as mandatory evacuation orders expanded.

Cal Fire Chief Ken Pimlott said the preliminary loss assessment of more than 1,500 residential and commercial structures was drawn from “very conservative estimates.”

Several incidents of looting had been reported by Monday afternoon, in both residential and commercial areas. Acting Santa Rosa Police Chief Schwartz ordered a curfew prohibiting anyone from being inside a mandatory evacuation zone between the hours of 6:45 p.m. and 7:15 a.m.

Sonoma County Sheriff Rob Giordano said scores of law enforcement personnel, including at least 120 on loan from neighboring counties, would patrol the fire areas in the days ahead, stopping and potentially arresting anyone unauthorized found inside.